| Bryconacidnus | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Characiformes |
| Family: | Characidae |
| Genus: | Bryconacidnus G. S. Myers, 1929 |
Bryconacidnus is a genus of characins found in tropical South America. [1]
There are currently 5 recognized species in this genus: [1]
The Poeciliidae are a family of freshwater fishes of the order Cyprinodontiformes, the tooth-carps, and include well-known live-bearing aquarium fish, such as the guppy, molly, platy, and swordtail. The original distribution of the family was the Southeastern United States to north of Río de la Plata, Argentina, and Africa, including Madagascar. Due to release of aquarium specimens and the widespread use of species of the genera Poecilia and Gambusia for mosquito control, though, poeciliids can today be found in all tropical and subtropical areas of the world. In addition, Poecilia and Gambusia specimens have been identified in hot springs pools as far north as Banff, Alberta.
In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistics it usually refers to the degree to which a pair of variables are linearly related. Familiar examples of dependent phenomena include the correlation between the height of parents and their offspring, and the correlation between the price of a good and the quantity the consumers are willing to purchase, as it is depicted in the so-called demand curve.
In statistics, the Pearson correlation coefficient (PCC) is a correlation coefficient that measures linear correlation between two sets of data. It is the ratio between the covariance of two variables and the product of their standard deviations; thus, it is essentially a normalized measurement of the covariance, such that the result always has a value between −1 and 1. As with covariance itself, the measure can only reflect a linear correlation of variables, and ignores many other types of relationships or correlations. As a simple example, one would expect the age and height of a sample of teenagers from a high school to have a Pearson correlation coefficient significantly greater than 0, but less than 1.
A chi-squared test is a statistical hypothesis test used in the analysis of contingency tables when the sample sizes are large. In simpler terms, this test is primarily used to examine whether two categorical variables are independent in influencing the test statistic. The test is valid when the test statistic is chi-squared distributed under the null hypothesis, specifically Pearson's chi-squared test and variants thereof. Pearson's chi-squared test is used to determine whether there is a statistically significant difference between the expected frequencies and the observed frequencies in one or more categories of a contingency table. For contingency tables with smaller sample sizes, a Fisher's exact test is used instead.
Pearson plc is a British multinational publishing and education company headquartered in London, England.
The Drosophilidae are a diverse, cosmopolitan family of flies, which includes species called fruit flies, although they are more accurately referred to as vinegar or pomace flies. Another distantly related family of flies, Tephritidae, are true fruit flies because they are frugivorous, and include apple maggot flies and many pests. The best known species of the Drosophilidae is Drosophila melanogaster, within the genus Drosophila, also called the "fruit fly." Drosophila melanogaster is used extensively for studies concerning genetics, development, physiology, ecology and behaviour. Many fundamental biological mechanisms were discovered first in D. melanogaster. The fruit fly is mostly composed of post-mitotic cells, has a very short lifespan, and shows gradual aging. As in other species, temperature influences the life history of the animal. Several genes have been identified that can be manipulated to extend the lifespan of these insects. Additionally, Drosophila subobscura, also within the genus Drosophila, has been reputed as a model organism for evolutionary-biological studies, along with D. sechellia for the evolution of host specialization on the toxic noni fruit and Scaptomyza flava for the evolution of herbivory and specialist on toxic mustard leaves.
Pearson Education, known since 2011 as simply Pearson, is the educational publishing and services subsidiary of the international corporation Pearson plc.
Tube-dwelling anemones or ceriantharians look very similar to sea anemones but belong to an entirely different class of anthozoans. They are solitary, living buried in soft sediments. Tube anemones live inside and can withdraw into tubes, which are composed of a fibrous material made from secreted mucus and threads of nematocyst-like organelles known as ptychocysts. Within the tubes of these ceriantharians, more than one polyp is present, which is an exceptional trait because species that create tube systems usually contain only one polyp per tube. Ceriantharians were formerly classified in the taxon Ceriantipatharia along with the black corals but have since been moved to their own class, Ceriantharia.
Astroblepus is a genus of fish in the family Astroblepidae found in South America and Panama. This genus is the only member of its family. These catfishes are primarily found in torrential streams in the Andean area. Astroblepus pholeter and A. riberae are troglobites adapted to living in subterranean water systems. These species are typically small, less than 10 cm (4 in). The largest species reaches 30 cm (1 ft). These fish have suckermouths like those of loricariids. They have two pairs of barbels, maxillary and nasal. The dorsal fin spine lacks a locking mechanism. These fish also have odontodes, tiny teeth on their skin. All species exhibit a conical, pointy type on their fin rays like that found in other loricarioids; other species also exhibit a blunt type that is only found on their skin.
Pearson's long-clawed shrew is a species of mammal in the family Soricidae. It is the only species within the genus Solisorex. It is endemic to Sri Lanka. Its natural habitats are subtropical or tropical dry forests and lowland grasslands. It is threatened by habitat loss. It is named after Joseph Pearson FRSE, Director of the Columbo Museum 1910-1933 who found it on 1 January 1924.
Erythrochampsa is an extinct genus of protosuchian crocodylomorph. Fossils have been found from the Red Beds of the Stormberg Group, the youngest group of strata from the Karoo Supergroup outcropping in South Africa.
Gammaflexiviridae is a family of viruses in the order Tymovirales. Fungi serve as natural hosts. There is only one genus in the family, Mycoflexivirus, which has one species: Botrytis virus F.
Arthur Anselm Pearson was an English mycologist. He often published under the name A. A. Pearson. The standard author abbreviation A.Pearson is used to indicate this person as the author when citing a botanical name.
Tulasnella is a genus of effused (patch-forming) fungi in the order Cantharellales. Basidiocarps, when visible, are typically smooth, ceraceous (waxy) to subgelatinous, frequently lilaceous to violet-grey, and formed on the underside of fallen branches and logs. They are microscopically distinct in having basidia with grossly swollen sterigmata on which basidiospores are formed. One atypical species, Tulasnella aurantiaca, produces orange to red, gelatinous, pustular anamorphs on wood. Some species form facultative mycorrhizas with orchids and liverworts. Around 80 species of Tulasnella are known worldwide.
Laemolyta is a genus of headstander found in the Orinoco and Amazon Basins in South America.
Astyanacinus is a genus of characins from South America. The currently recognized species in this genus are:
Prodontocharax is a genus of characins found in tropical South America, with three currently described species:
Pyrrhulina is a genus of freshwater fishes found in tropical South America. Several of these species are popular aquarium fish.
Phenacorhamdia is a genus of three-barbeled catfishes native to tropical South America.
Rhamdella is a genus of three-barbeled catfishes native to South America.
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